Board of Directors

Larry Hull, President..........................................Precinct 1

Jim Bower, Vice-President ................................Precinct 2

David Davenport, Treasurer .............................At-Large

Larry Sunn, Secretary........................................Bulverde-Spring Branch

Jensie Madden..................................................Precinct 4

Rob Johnson ......................................................At-Large

Clinton Dietert ...................................................Precinct 3

District Staff

H.L. Saur, General Manager

Emily Green, Administrator

Comal Trinity GCD PO BOX 664 Spring Branch, Texas 78070

830-885-2130 www.comaltrinitygcd.com

COMAL TRINITY

GROUNDWATER CONSERVATION DISTRICT

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Comal Trinity Groundwater Conservation District Management Plan Revision Record

Date Adopted Effective Date Version/Resolution

3/19/2018 Original Adoption

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TABLE OF CONTENTS TIME PERIOD FOR THIS PLAN ........................................................................................................................ 4

DISTRICT MISSION ......................................................................................................................................... 4

GUIDING PRINCIPLES .................................................................................................................................... 4

GENERAL DESCRIPTION OF THE DISTRICT ..................................................................................................... 5

TOPOGRAPHY AND DRAINAGE ..................................................................................................................... 6

GROUNDWATER RESOURCES AND USAGE WITHIN CTGCD .......................................................................... 8

TRINITY AQUIFER AND ITS SUBDIVISIONS .................................................................................................... 9

SURFACE WATER RESOURCES AND USAGE WITHIN CTGCD ....................................................................... 10

JOINT PLANNING IN MANAGEMENT AREA ................................................................................................. 11

MODELED AVAILABLE GROUNDWATER BASED ON DESIRED FUTURE CONDITIONS FOR GMA 9 .............. 12

MODELED AVAILABLE GROUNDWATER BASED ON DESIRED FUTURE CONDITIONS FOR GMA 10 ............ 13

PROJECTED TOTAL WATER DEMAND WITHIN CTGCD ................................................................................ 14

ESTIMATES OF TECHNICAL INFORMATION REQUIRED BY TWC SECTION 36.1071 AND 31 TAC 356.52 .... 14

ACTIONS, PROCEDURES, PERFORMANCE AND AVOIDANCE NECESSARY TO EFFECTUATE THE

MANAGEMENT PLAN INCLUDING HOW THE DISTRICT WILL MANAGE GROUNDWATER SUPPLIES .......... 15

METHODOLOGY FOR TRACKING PROGRESS IN ACHIEVING MANAGEMENT GOALS .................................. 16

REFERENCES ................................................................................................................................................ 20

LIST OF TABLES

TABLE 1. POPULATION PROJECTIONS SOUTH CENTRAL TEXAS REGION, COMAL COUNTY......................... 7

TABLE 2. GROUNDWATER USAGE (IN AC-FT) BY WATER USER GROUP 2016, CTGCD……........................... 9

TABLE 3. MAG FOR THE TRINITY AQUIFER, GMA 9, GAM RUN 16-023, MAG

COMAL COUNTY (IN AC-F-T)…………………………………………………………………………………………..........................13

TABLE 4. MAG FOR THE TRINITY AQUIFER, GMA 10, AA 10-29 MAG,

COMAL COUNTY (IN AC-FT)……………………………………………………………….…………………….…………….................14

TABLE 5. DISTRICT GROUNDWATER FLOW BUDGET AND RECHARGE VARIABLE...................................... 15

APPENDICES

APPENDIX A – TWDB GAM 16-023 MAG, GMA 9 Resolution, and GMA 10 Resolution

APPENDIX B – GAM Run 16-022: Comal Trinity Groundwater Conservation District Management Plan

APPENDIX C – CTGCD Board Resolution 2202017

APPENDIX D – GTA Aquifer Assessment 10-29 MAG

APPENDIX E – TWDB Estimated Historical Groundwater Use and 2017 State Water Plan

Datasets: Comal Trinity Groundwater Conservation District

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TIME PERIOD FOR THIS PLAN

This plan becomes effective upon adoption by the Comal Trinity Groundwater Conservation

District (CTGCD) board of directors and subsequent approval by the Texas Water Development Board

(TWDB). Every five years thereafter, in accordance with Texas Water Code 36.1072 (e), the plan will be

reviewed for consistency with the applicable Regional Water Plans, the State Water Plan, and

Groundwater Management Areas 9 (GMA 9) and 10 (GMA 10) Desired Future Conditions (DFCs) and shall

be readopted with or without amendments. The plan may be revised at any time to maintain consistency

or as necessary to address any new or revised data, Groundwater Availability Models, Desired Future

Conditions in GMA 9 and/or GMA 10, or district management strategies.

This plan incorporates a planning period of 50 years. Population and water demand projections

cover the 50-year period from 2020 to 2070 and are consistent with those used by the TWDB for this area

in statewide water planning. Upon its approval by the TWDB, this Plan will remain in effect until a revised

Plan is submitted and approved, or for five years from the approval date, whichever is earlier.

DISTRICT MISSION

The Comal Trinity Groundwater Conservation District (CTGCD or district) was created under

Chapter 36 of the Texas Water Code for the purpose of conserving, preserving, recharging, protecting and

preventing waste of groundwater from the Trinity Aquifer and its subdivisions within Comal County. The

district will conduct administrative and technical activities and programs to achieve these purposes. The

district will use the authority granted under its enabling legislation, HB2407, and TWC Chapter 36 and

other state laws to conduct aquifer research, monitor water well drilling and production from non-exempt

wells, collect and archive well water and aquifer data, issue authorizations for well drilling, modification,

equipping, and plugging, promote the capping or plugging of abandoned wells, provide information and

educational material to local property owners, interact with other governmental or organizational

entities, and incorporate other groundwater-related activities that may help meet the purposes of the

district.

GUIDING PRINCIPLES

The CTGCD was created in order that appropriate groundwater management techniques and

strategies could be implemented at the local level to address groundwater issues or concerns within the

district. The district will incorporate the best and most current site-specific data available in the

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development of this plan to ensure the sustainability of the Trinity Aquifer and its subdivisions and

achievement of the Desired Future Conditions (DFCs).

The district recognizes that groundwater resources throughout this region are of vital importance

to all citizens and that these resources must be managed effectively. This plan serves as a guideline for

the district to ensure greater understanding of local aquifer conditions, development of groundwater

management concepts and strategies, and subsequent implementation of appropriate groundwater

management policies.

GENERAL DESCRIPTION OF THE DISTRICT

The Comal Trinity Groundwater Conservation District comprises the majority of Comal County,

excluding a small portion of territory included within the boundaries of the Trinity Glen Rose Groundwater

Conservation District.

CTGCD DISTRICT BOUNDARY

Source: CTGCD

The district is overseen by a 7-member board of directors appointed by the Comal County

Commissioners Court. Directors serve staggered 4 year terms. The district currently employs one part-

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time general manager and one part-time administrative staff. The district finalized and approved well

registration rules and a fee schedule for non-exempt wells in December 2015.

Covering 559 square miles, Comal County resides within two Groundwater Management Areas.

The western portion of the county lies within GMA 9 and as such falls within the Hill Country Priority

Groundwater Management Area. This designation, originally described by the Texas Water Commission –

now referred to as the Texas Commission on Environmental Quality (TCEQ)--- in 1990, is defined as an

area experiencing or expected to experience quality or quantity issues within the next 50 years. Western

Comal County is primarily rural in make-up; however, the southern portion of the county is experiencing

considerable growth in terms of population and development around the city of Bulverde. The eastern

portion of Comal County lies within GMA 10 and can be characterized as urban or rapidly urbanizing with

development primarily occurring along IH-35. New Braunfels, the county seat and largest city, with a

population of 57,740, lies within GMA 10. Per the U.S. Census Bureau, the 2010 population for Comal

County was 108,472 (US Census Bureau, 2010).

The most recently approved regional water plan is the 2016 South Central Texas Regional Water

Plan which utilizes population projections provided by TWDB in order to develop water plans to meet

future water needs. These population projections for Comal County are summarized below.

Table 1. Population Projections South Central Texas Region, Comal County

COUNTY YEAR

2020 2030 2040 2050 2060 2070

Comal 140,825 178,399 216,562 255,092 293,362 330,099

Source: 2016 South Central Texas Regional Water Plan Volume I

TOPOGRAPHY AND DRAINAGE

Comal County lies within the San Antonio River and Guadalupe River basins. The Guadalupe

River Basin extends across the northern three-quarters of Comal County with the remaining quarter

falling within the San Antonio River Basin. Flowing into Canyon Lake, a Guadalupe-Blanco River Authority

(GBRA) managed reservoir and the primary surface water provider for Comal County, the Guadalupe

River continues southeast upon exiting the reservoir to New Braunfels and into Guadalupe County.

The county contains numerous watersheds including Upper and Lower Blanco River, Cibolo Creek,

Comal River, and Upper San Marcos. Surface drainage within the district is generally west to southeast.

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DISTRICT RIVER BASINS

Source: TWDB; Groundwater Data Viewer

The primary geologic features contributing to the topography within the district are the Edwards

Plateau and the Balcones Escarpment (Balcones Fault Zone). Below this escarpment the landscape

transitions into the Upper Gulf Coastal Plain region.

The Edwards Plateau is characterized as a broad, topographically high area composed of

Cretaceous age limestone, dolomite and marl. Deep erosion and down cutting by streams and rivers in

the area have resulted in the Edwards Plateau being perceptibly higher than adjacent areas. The plateau

is the southernmost extension of the Great Plains, extending westward from the Colorado River to the

Pecos, and covers many Central and West Texas counties. It is bordered on the northeast by the

Precambrian rocks of the Llano Uplift. Comal County lies near the southeastern edge of the Edwards

Plateau.

Elevation within the district ranges from a high of approximately 1,527 feet above sea level at

Devil’s Hill, seven miles west of Smithson Valley to a low of 600 feet above sea level where the

Guadalupe River enters Guadalupe County (George et al. 1952).

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GROUNDWATER RESOURCES AND USAGE WITHIN CTGCD

The major aquifer managed by the CTGCD providing groundwater to residents is the Trinity

Aquifer and its subdivisions consisting of the Upper Glen Rose Limestone, Lower Glen Rose Limestone,

Cow Creek Limestone, Sligo Limestone and Hosston Sand. The Edwards Aquifer, overseen by the Edwards

Aquifer Authority, overlies portions of the Trinity Aquifer and its subdivisions throughout the eastern one-

third of Comal County. Wells to be completed into the Edwards Aquifer must obtain a permit through the

Edwards Aquifer Authority. In areas where a well is to be completed into the Trinity Aquifer and its

subdivisions, but must pass through a portion of the Edwards Aquifer, the driller must obtain a “pass

through” permit from the Edwards Aquifer Authority.

Depths are highly variable within the Trinity Aquifer and its subdivisions and depend entirely on

site-specific topography and geology, especially faulting. Water quality and water quantity also vary

greatly throughout the district.

According to the Historical Water Use Survey Data (2000-2015) provided by the Texas Water

Development Board in Appendix E, groundwater has supplied the majority of water needs for all water

user groups, excluding livestock over the last several years, with municipal users commanding the largest

share. It should be noted that the totals provided within TWDB’s Historical Water Use Survey Data include

groundwater drawn from both the Edwards and Trinity Aquifers.

The district began collecting groundwater pumpage data from non-exempt wells January 1, 2016.

Pumpage amounts categorized by Water User Group (WUG) are provided in Table 2 and reflect

groundwater produced from the Trinity Aquifer and its subdivisions only. The accompanying graph depicts

the percentage of total groundwater use categorized by WUG.

Table 2. Groundwater Usage (in ac-ft) by Water User Group 2016, CTGCD1

WUG 2016

Municipal/PWS 4684.29

Industrial 743.61

Irrigation 216.60

Small Business 68.09

Federal Exempt 21.57

Exempt 327.00

1Comal Trinity Groundwater Conservation District Pumpage Database. Values collected through non-exempt user pumpage reports.

Exempt Number provided by TWDB, Projected Exempt Groundwater Use Estimates December 2015

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CTGCD 2016 PERCENT OF TOTAL REPORTED PUMPAGE PER WUG

TRINITY AQUIFER AND ITS SUBDIVISIONS

The Trinity Aquifer extends across much of the central and northeastern part of the state. It is

composed of several smaller aquifers contained within the Trinity Aquifer and its subdivisions. These

aquifers consist of limestones, sands, clays, gravels, and conglomerates. Their combined freshwater

saturated thickness averages about 600 feet in North Texas and about 1,900 feet in Central Texas. In

general, groundwater is fresh but very hard in the outcrop of the aquifer. Total dissolved solids increase

from less than 1,000 milligrams per liter in the east and southeast to between 1,000 and 5,000 milligrams

per liter, or slightly to moderately saline, as the depth to the aquifer increases. Sulfate and chloride

concentrations also tend to increase with depth. The Trinity Aquifer discharges to a large number of

springs, with most discharging less than 10 cubic feet per second. The aquifer is one of the most extensive

and highly used groundwater resources in Texas (George et al. 2011).

Municipal/PWS77%

Industrial12%

Irrigation4%

Small Business

1%

Federal Exempt<1% Exempt

6%

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Structural cross section across the Trinity Aquifer in the Hill Country, including rocks from the Upper Glen Rose Formation to the

Hosston Sand (modified from Ashworth, 1983; Mace and others, 2000b).

SURFACE WATER RESOURCES AND USAGE WITHIN CTGCD

Canyon Lake is the major surface water resource within the district. Canyon Lake Water Service

Company has up to 6,000 ac-ft/yr of surface water allotments from Canyon Lake managed by Guadalupe-

Blanco River Authority (GBRA), 722 ac-ft/yr of surface water from the Western Canyon project for use in

the Bulverde area with the remaining 130 ac-ft/yr surface water sourced from the Guadalupe River above

Canyon Lake (CLWSC Water Availability Report, April 2016).

New Braunfels Utilities (NBU) is the largest water supplier for the eastern portion of the district. According

to data provided in the 2016 Region L Water Plan, surface water supplies include 8,072 ac-ft/yr of

purchased water from the Canyon Reservoir, 1,072 ac-ft/yr of Guadalupe Run-of-River rights, 4,590 ac-

ft/yr from the Edwards Aquifer, and 536 ac-ft/yr supplied from the Trinity Aquifer (2016 South Central

Texas Regional Water Plan, 2015).

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JOINT PLANNING IN MANAGEMENT AREA

Every five years, the groundwater conservation districts in GMA 9 and GMA 10 shall consider

groundwater availability models and other data for these management areas and shall establish desired

future conditions for the relevant aquifers within the management areas. In establishing the desired

future conditions of the aquifers under this section, the districts shall consider uses or conditions of an

aquifer within the management area that differ substantially from one geographic area to another.

The GMAs may establish different desired future conditions for each aquifer, subdivision of an

aquifer, or geologic strata located in whole or in part within the boundaries of the management area; or

each geographic area overlying an aquifer in whole or in part or subdivision of an aquifer within the

boundaries of these management areas. The Texas Water Development Board will calculate the Modeled

Available Groundwater (MAG) from the adopted Desired Future Conditions (DFC) of these management

areas.

GROUNDWATER MANAGEMENT AREA (GMA) 9:

Source: TWDB; http://www.twdb.texas.gov/groundwatermanagement_areas/maps/GMA9_GCD.pdf

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MODELED AVAILABLE GROUNDWATER BASED ON DESIRED FUTURE CONDITIONS FOR GMA 9

Modeled Available Groundwater (MAG) is defined in TWC Section 36.001 as “the amount of water

that the executive administrator determines may be produced on an average annual basis to achieve a

desired future condition established under Section 36.108.” The Desired Future Condition (DFC) of an

aquifer may only be determined through Joint Planning with other Groundwater Conservation Districts

(GCDs) within the same Groundwater Management Area in accordance with TWC 36.108. The GCDs within

Groundwater Management Area 9 adopted the second round of DFCs on April 28, 2016 with an

amendment made on October 24, 2016 (Jones, 2017). These adopted DFCs approved by GMA 9 are found

in Appendix A reflecting a Total Modeled Available Groundwater amount for the Trinity Aquifer and its

subdivisions located within GMA 9 and underlying CTGCD as 10,076 ac-ft/yr (2010-2060) as reflected in

Table 3 (GR16-023 MAG). The board of directors for CTGCD adopted these DFCs by resolution on February

20, 2017. This resolution can be found in Appendix C. The CTGCD was not in existence during the first

round of DFC planning nor during the first half of the second round of the DFC planning process. It should

be noted however, during the joint planning process to adopt DFCs for 2016, the GMA 9 committee invited

a representative from Comal County to act as a non-voting member. Upon creation of the district, CTGCD

became a voting member within the GMA 9 Joint Planning Committee.

Table 3. MAG for the Trinity Aquifer, GMA 9, Comal County (in ac-ft), GMA Run 16-023 MAG

COUNTY YEAR

2010 2020 2030 2040 2050 2060

Comal 10,076 10,076 10,076 10,076 10,076 10,076

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GROUNDWATER MANAGEMENT AREA (GMA) 10:

Source: TWDB; http://www.twdb.texas.gov/groundwater/management_areas/maps/GMA10_GCD.pdf

MODELED AVAILABLE GROUNDWATER BASED ON DESIRED FUTURE CONDITIONS FOR GMA 10

The GCDs within Groundwater Management Area 10 completed the first round of the DFC joint

planning process on August 23, 2010. The adopted DFCs approved by GMA 10 are found in Appendix D

reflecting a Total Modeled Available Groundwater amount for the Trinity Aquifer and its subdivisions

located within GMA 10 boundaries and underlying CTGCD is 29,284 ac-ft/yr (2010-2060) as reflected in

Table 4 (AA 10-29 MAG).

The CTGCD was not in existence during this first round of DFC planning. Upon creation of the

district, CTGCD became a voting member within the GMA 10 Joint Planning Committee.

Table 4. MAG for the Trinity Aquifer, GMA 10, Comal County (in ac-ft), AA 10-29 MAG

COUNTY YEAR

2010 2020 2030 2040 2050 2060

Comal 29,284 29,284 29,284 29,284 29,284 29,284

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PROJECTED TOTAL WATER DEMAND WITHIN CTGCD

The projected total annual water demand in Comal County is summarized in Appendix E. Taking

population projections incorporated in the 2016 Region L Water Plan into consideration, it is anticipated

the greatest demand on water resources will be from municipal users despite projected declines in per

capita use.

ESTIMATES OF TECHNICAL INFORMATION REQUIRED BY TWC SECTION 36.1071 AND 31 TAC 356.52

Table 5 provides a groundwater flow budget and recharge variables for the district. TWDB

conducted this analysis using the groundwater availability model for the Hill Country portion of the Trinity

Aquifer System. Table 5 addresses some of the flow variables that affect recharge calculations and is

derived from GAM Run 16-022 located in Appendix B.

Table 5. District Groundwater Flow Budget and Recharge Variable

Management Plan Requirement Aquifer or Confining Unit Results (ac-ft/yr)

Estimated annual amount of recharge from precipitation to the district

Trinity Aquifer System 42,457

Estimated annual volume of water that discharges from the aquifer to springs and any surface water body including lakes, streams, and rivers

Trinity Aquifer System 15,601

Estimated annual volume of flow into the district within each aquifer in the district

Trinity Aquifer System 38,106

Estimated annual volume of flow out of the district within each aquifer in the district

Trinity Aquifer System 28,422

Estimated net annual volume of flow between each aquifer in the district

From the Trinity Aquifer System to the Edwards (Balcones Fault Zone) Aquifer and deep Trinity Aquifer

38,912*

* In the Comal Trinity Groundwater Conservation District, groundwater generally flows southeast from the Trinity Aquifer System

to the Edwards (Balcones Fault Zone) Aquifer and the confined parts of the Trinity Aquifer System that underlie the Edwards (Balcones Fault Zone) Aquifer

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ACTIONS, PROCEDURES, PERFORMANCE AND AVOIDANCE NECESSARY TO EFFECTUATE THE

MANAGEMENT PLAN INCLUDING HOW THE DISTRICT WILL MANAGE GROUNDWATER SUPPLIES

The district will manage the supply of groundwater within the district based on the district’s best

available data and its assessment of water availability and groundwater storage conditions. The most

current Groundwater Availability Model and Modeled Available Groundwater values developed by the

TWDB for the Trinity Aquifer and its subdivisions or other groundwater models, as well as other studies

performed by other entities, will also aid in the decision-making process by the district.

The District will use the management plan to guide the district in its efforts to preserve and

protect the groundwater resources within Comal County. The district will ensure that rule development,

regulatory activities, planning effects and daily operations are consistent with the management plan. The

rules for the district will be developed in coordination with the management goals and technical

information provided in the management plan. The rules shall be consistent with the provision of the

management plan and Chapter 36 of the Texas Water Code.

The district has adopted rules that require the registration of non-exempt wells within the district

consistent with the district’s management plan, the provisions of Chapter 36.113, and other pertinent

sections of Chapter 36. District rules can be found at https://www.comaltrinitygcd.com/rules-f4x40

The district is committed to working and planning with other GCDs in Groundwater Management Areas 9

and 10. The district will use the management plan as part of its cooperative efforts with the neighboring

GCDs. The District will manage the supply of groundwater within the district based on Desired Future

Conditions and Modeled Available Groundwater resulting from the Groundwater Management Areas 9

and 10 cooperative planning processes, production demand from exempt and non-exempt wells, and the

district’s best available data.

The district will seek cooperation and coordination in the development and implementation of

this plan with the appropriate state, regional or local water management or planning entities.

The district shall review and re-adopt this plan, with or without revisions, at least once every five years in

accordance with Chapter 36.1072(e). Any amendment to this plan shall be in accordance with Chapter

36.1073.

The district will encourage cooperative and voluntary rule compliance, but if rule enforcement

becomes necessary, the enforcement will be legal, fair, and impartial.

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METHODOLOGY FOR TRACKING PROGRESS IN ACHIEVING MANAGEMENT GOALS

District staff will present an annual report to the board of directors on district performance and

progress in achieving management goals and objectives for the preceding fiscal year.

GROUNDWATER MANAGEMENT GOALS

1.0 Implement management strategies that will provide for the most efficient use of groundwater.

1.A Management Objective

Within five years of the adoption of this management plan, the district will implement and maintain

a program of issuing well operating permits for non-exempt wells within the district

Performance Standard

Upon implementation of operating permit issuance system, the number of well operating permit

applications and the number of permits issued will be presented and discussed in the annual report

to the district board of directors

1.B Management Objective

Ongoing program of quarterly collection and record-keeping of actual meter readings from non-

exempt wells to quantify Trinity groundwater withdrawal from non-exempt water wells within the

district

Performance Standard

Annual report submitted to the board of directors will record acre-ft of Trinity groundwater pumped

by non-exempt wells during the preceding fiscal year

2.0 Implement strategies that will control and prevent waste of groundwater.

2.A Management Objective

Each year the district will provide information on the importance of controlling and preventing waste of groundwater through one or more of the following methods:

• Article provided to local media and/or community news

• Distribution of water conservation literature at public meetings or events

• Information on the district website

• Maintain water conservation literature at the district office

Performance Standard Number of articles provided to local news media and/or newsletters, and number of water conservation literature handed out to the public will be provided in the annual report to the district board of directors.

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3.0 Implement strategies that will control and prevent subsidence.

The rigid geologic framework of the region precludes subsidence from occurring. Therefore, this goal is

not applicable to the operations of this district.

4.0 Implement management strategies that will address conjunctive surface water management

issues.

4.A Management Objective

The General Manager or one designated board member of the CTGCD will at least once per year attend and participate in GMA 9 and 10 activities. The district will participate in the regional water planning process by attending at least one meeting annually of the Region L planning group to encourage development of alternative water supplies.

Performance Standard Attendance of these meetings will be reported to the board of directors during regular board meetings

4.B Management Objective

Within five years of the adoption of this management plan, 2 wells completed to the Middle Trinity will be designated and monitored by the District on at least a quarterly basis. Performance Standard Upon designation of monitor wells, water levels will be provided to the board of directors on a quarterly basis.

5.0 Implement strategies that will address natural resource issues which impact the use and availability

of groundwater, or which are impacted by the use of groundwater.

The district is not currently aware of any natural resource issues impacted by the Trinity Aquifer. Therefore this goal is not applicable.

6.0 Implement strategies that will address drought conditions.

6.A Management Objective The district will collect drought condition information on a, at minimum, quarterly basis related to Comal County and the surrounding region utilizing the Palmer Drought Severity Index. Performance Standard Drought condition information will be summarized and discussed at least quarterly during district board meetings.

6.B Management Objective Collect and provide information on precipitation patterns across Comal County as recorded by the National Weather Service on a quarterly basis.

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Performance Standard Report precipitation conditions to the district board of directors during regular board meetings on an, at minimum, quarterly basis.

7.0 Implement strategies that will address:

Conservation

7.A Management Objective Within one year of the adoption of this management plan, the district will maintain on the district’s website information regarding the importance of groundwater conservation and water conservation methods. Performance Standard Maintain a record of “hits” to conservation information on the website; include in annual report to the district board of directors. 7.B Management Objective Within one year of the adoption of this management plan, the district will make available handouts containing water conservation information at public information events or other locations, such as district office. Performance Standard Report the number of handouts provided and a list of events or other locations where provided in annual report to the district board of directors. 7.C Management Objective Within one year of the adoption of this management plan, the district will prepare a presentation describing the purpose of CTGCD and including information about water conservation for meetings of local organizations. Performance Standard Report the number of presentations offered to local organizations in annual report to the district board of directors. Recharge Enhancement

7.D Management Objective The district will investigate potential recharge enhancement sites either natural or artificial Performance Standard Annually, the General Manager will include a report to the board of directors on the district’s findings related to recharge enhancement

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Rainwater Harvesting

7.E. Management Objective Within one year of the adoption of this management plan, the district will maintain on the district’s website information on rainwater harvesting and links to resources.

Performance Standard Maintain a tally of “hits” to rainwater harvesting information on the website; provide this information in annual report to the district board of directors. Precipitation Enhancement

The precipitation enhancement goal is not applicable to the district as this objective is not currently effective at this time.

Brush Control

7.F Management Objective Within one year of the adoption of this management plan, the district will acquire and provide handouts containing brush control information to promote recharge and protect water quality, to include best practices regarding management of ashe juniper, and provide the handouts at public information events or other locations.

Performance Standard Report the number of handouts provided and a list of events or other locations where provided in an annual report to the district board of directors. 8.0 Addressing Desired Future Conditions

8.A Management Objective Within five years of the adoption of this management plan, the district will begin to monitor the water level in the Trinity Aquifer on a quarterly basis to ensure the achievement of the DFC adopted GMA 9 and GMA 10. Performance Standard The district will monitor the water level in at least one district-designated monitor well and compare with the average drawdown and allowable drawdown resulting from the DFC process. The data will be presented to the district board of directors in an annual report, reviewed by the district at least once every five years, and presented to GMA 9 and GMA 10 as required under TWC 36.108.

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REFERENCES

2016 South Central Texas Regional Water Plan, Volume I — Executive Summary and Regional Water

Plan, December 2015.

Allen, S. 2016, Estimated Historical Use and 2017 State Water Plan Datasets: Comal Trinity Groundwater

Conservation District. Texas Water Development Board, September 20, 2017.

Canyon Lake Water Service Company, Water Availability Report, April 2016.

Comal Trinity Groundwater Conservation District, Pumpage Database.

George, P.G., Mace, R E., and Petrossian, R., 2011, Aquifers of Texas, Report 380, Texas Water

Development Board, Austin, TX.

George, W.O., S. D. Breeding, and W. W. Hastings, 1952, Geology and ground-water resources of Comal

County, Texas. USGS Water Supply Paper 1138.

Jones, I., 2017, GAM Run 16-023 MAG: Modeled Available Groundwater for the Aquifers in Groundwater

Management Area 9: Texas Water Development Board.

Thorkildsen D. and Backhouse S., 2010, GTA Aquifer Assessment 10-29: Texas Water Development

Board, GTA Aquifer Assessment 10-29 Report, 11 p.

Texas Water Development Board, Groundwater Availability Model (GAM) 15-001

U.S. Census Bureau, United States Census (2010)

APPENDIX A - TWDB GAM 16-023 MAG, GMA 9 Resolution and GMA 10,

Resolution

APPENDIX B – GAM Run 16-022: Comal Trinity Groundwater Conservation

District Management Plan

APPENDIX C – CTGCD Board Resolution 2202017

APPENDIX D – GTA Aquifer Assessment 10-29 MAG

APPENDIX E - Estimated Historical Groundwater Use and 2017 State Water Plan

Datasets: Comal Trinity Groundwater Conservation District